In a telecommunication network, a network management is necessary. The network management is executed by operations for getting a value of a management object item, for setting value of a management object item, and for reporting an event. For this purpose, a message is transferred between a manager and an agent based on a predetermined network management protocol. The manager is a module for managing, the agent is a module to be managed.
The manager commands an operation for a managed information to the agent. The manager interacts with an operator through an interface and, if necessary, stores and analyzes the managed information and an event transferred from the agent.
The agent operates a managed item according to the command from the manager and sends its result to the manager. The agent detects an accident and a change of a status, and sends them as the event to the manager.
As network protocols, SNMP and CMIP are mainly used. SNMP is a "Simple Network Management Protocol" and CMIP is a "Common Management Information Protocol".
A management information in SNMP agent is a gathering of management object items. Then, the management information seems to be a virtual database and it is called as MIB (Management Information Base).
It is necessary to define an ID name of the management object items of SNMP and an MO (Managed Object) of CMIP and also to define a syntax of a value, for accessing the management object items of SNMP or the MO of CMIP. However there is a difference of a definition between SNMP and CMIP.
SNMP is a network protocol used in the Internet, then it is a defacto standard for monitoring and controlling a device in LAN (Local Area Network). A specification of SNMP is prescribed by documents such as RFC (Request For Comments) 1157, under IETF (Internet Engineering Task Force) of IAB (Internet Activities Board). SNMP is more simple in management operation and management information than CMIP.
There are five management operations in SNMP for simplicity as follows (1).about.(5).
(1) Get-Request: Request for getting a management object information
(2) Get-NextRequest: Request for getting an item next to the management object information
(3) Set-Request: Request for setting a management object information
(4) Get-Response: Response to any one of above-mentioned request
(5) Trap: Report for an event occurred in the agent
The management information in SNMP is defined by SMI (Structure of Management Information) standardized by RFC 1155 etc..
Namely, in SNMP, one Object Name is assigned to one management object item based on an object registration tree. As syntax of a value of the management object item, for simplicity, only simple types (INTEGER-type, OCTET STRING-type, OBJECT IDENTIFIER-type and NULL-type) are allowed to use out of data-types in ASN.1 (Abstract Syntax Notation One).
There is a so-called entry in SMI of which concept is a group of management object items. As shown in FIG. 28, SEQUENCE-type in ASN.1 is used for a syntax of the entry which is called as a list-type. However, all components defined in the list-table must be included within data and a data-type of each component must be one of above-mentioned simple-types.
Furthermore, as shown in FIG. 29, SEQUENCE OF-type is used only when the SEQUENCE OF-type indicates a table of the entry, then the SEQUENCE OF-type is called as a table-type. An n-th entry of the table-type is identified by using "n" as an index for discriminating other entries.
In a case to get or set a value of a certain management object item in SNMP, if the management object item is a component of an entry, an operation such as "GetRequest" is done by using an index for discriminating the entry in its table, for example, by designating its object name and .n!, wherein "n" indicates its order in the table. In the case to operate a management object item "ifIndex(1)" in an entry "ifEntry(1)" shown in FIG. 30, 1.3.6.1.2.1.2.2.1.1.n! is designated by using its object name 1.3.6.1.2.1.2.2.1.1! and its index .n! in the table-type.
Namely, in the management operation of SNMP, it is impossible to operate all over the entries or it is impossible to operate all values of the list-type by one operation. Also, it is impossible to operate the table itself.
On the other hand, in a case to get or set a value of a management object item which is independent from the entry, an operation such as "GetRequest" is done by using an index 0! which indicates that the item is not included within the entry, for example, by designating its object name and .0!. In the case to operate a management object item "ifNumber(1)" shown in FIG. 30, 1.3.6.1.2.1.2.1.0! is designated.
In addition to above-mentioned four simple types, in SNMP, six data-types are defined. They are Networkaddress!,IpAddress!, Counter!,Gauge!,TimeTicks! and Opaque!.
The Opaque-type is used for transferring, between the agent and the manager, an arbitrary data which is encoded by an encoding rule of AS N.1 (for example, BER (Basic Encoding Rule)) and which is supposed to be OCTET STRING-type.
FIG. 31 shows a network management system which monitors and controls LAN devices by using SNMP. In FIG. 31, an SNMP manager 100 is a workstation or a personal computer having an SNMP interface 101. The SNMP manager 100 is connected to an SNMP agent 200. The SNMP agent 200 has an SNMP interface 201, but the SNMP interface 201 is installed in a LAN device 300 on a network. 202 denotes an MIB for LAN device 300 under management of the SNMP agent 200.
CMIP is a protocol for managing a network and a system in OSI (Open System Interconnection) based on ISO (International Standard Organization). CMIP is prescribed by ISO/IEC 9596-1 etc..
In TMN (Telecommunication Management Network) standardized by ITU-CMIP and GDMO (Guidelines for the Definition of Managed Object: ISO/IEC 10165-4) are used for monitoring and controlling a telecommunication network.
Function of CMIP is higher and more complex than SNMP in management operation and in managed information. Further, GDMO is more complex than SMI.
There are seven management operations in CMIP as follows (1).about.(7) in a general classification. In each operation, there are four modes of "req" (request: for example, M-GETreq), "ind" (indication: for example, M-EVENTREPORTind), "rsp" (response: for example, M-EVENTREPORTrsp) and "cnf" (confirmation: for example, M-GETcnf).
(1) M-GET: Request for getting an attribute of a managed object
(2) M-SET: Request for setting an attribute of a managed object
(3) M-CREATE: Creation of a managed object
(4) M-DELETE: Deletion of a managed object
(5) M-ACTION: Instruction of an action to a managed object
(6) M-EVENTREPORT: Report for an event occurred in a managed object
(7) M-CANCEL-GET: Cancellation of a preceding M-GETreq
Managed information of CMIP is prescribed by GDMO. Namely, a management object in OSI management is called as Managed Object, it is deferent from SNMP that Managed Object is expressed by a Managed Object (MO) class and an object instance.
It is possible for Managed Object to have arbitrary numbers of Attributes, and it is possible to definite an action which Managed Object can take and an event which can occur in Managed Object.
As a sample of the Attributes in a printer, there are a name, a type, an interface, a number of sheets in a period. As a sample of the actions, there are a self-test and mode-conversion. As a sample of the events, there are a lack of toner and a jam of a paper.
A group of Managed Objects having same attribute or same action is called as Managed Object Class. Each instance of a Managed Object in a Managed Object Class is called as an object instance.
An object of the management operation by CMIP is the object instance. In CMIP, it is possible to get or set all of the values of the attribute of the object instance at once, by designating an MO class and an object instance.
As mentioned-above, because the object instance is a managed object in a certain managed object class, it is possible to have arbitrary numbers of attributes and it is possible to use all of simple and structural data-types of ASN.1.
FIG. 32 shows a network managing system which monitors and controls TMN devises (devices based on TMN) by using CMIP. In FIG. 32, an OSI manager 400 is a manager having a CMIP interface 401. The OSI manager 400 is connected to an OSI management agent 500. The OSI management agent 500 has an CMIP interface 501, but the CMIP interface 501 is installed in a TMN device 600. 502 denotes an MIB for TMN device 600 under the management of the OSI management agent 500.
Recently, because of a progress of a standardization in TMN, TMN devices having CMIP are introduced into telecommunication carriers. SNMP is widely used in LAN devices and is introduced into many workstations. Further, there are personal computers having a function of SNMP manager.
Therefore, it is necessary to be able to monitor and control TMN devices by using cheap and simple SNMP manager 100, because OSI manager 400 is expensive and complex. For example, if possible, it is useful that user's SNMP manager 100 monitors and controls TMN device 600 for CNM (Customer Network Management). In CNM, it is released for a user to control a telecommunication network of a telecommunication carrier. In CNM, such information of an obstacle or a performance of the telecommunication network are supplied to the user.
However, in the prior art, it was impossible to manage OSI management agent 500 of TMN device 600 by SNMP manager 100 because CMIP is more complex than SNMP in protocol and management information.
IIMC system is considered as a method which manages TMN device by SNMP manager, wherein IIMC denotes ISO/CCITT and International Management Coexistence in NMF (Network Management Forum).
In the IIMC system, as shown in FIG. 33, OSI management agent 500 for TMN device 600 and SNMP agent 700 are simultaneously used. Further more, the SNMP agent 700 has a definition conversion part 702 which converts a definition of the CMIP management information to a definition of the SNMP management information. The SNMP manager 100 manages the SNMP agent 700, then monitors and controls the TMN device 600. 701 denotes an SNMP interface.
Therefore, in the IIMC system, a rule of relationship between MIB 502 of OSI management and MIB of SNMP is prescribed.
As mentioned-above, MO class and attribute are defined as a management information of OSI management by the GDMO.
In the IIMC system, each management object class in GDMO of OSI management corresponds to a table and an entry of SNMP, and each attribute in GDMO of OSI management corresponds to component in the entry of SNMP (management object item).
However, in a case of correspondence to an attribute of a structural type, a syntax of the structural type is divided to plural objects of simple types by using a pointer, a side-table and an entry because structural types (SEQUENCE-type,CHOICE-type etc.) can not be used in SNMP. The pointer indicates a connection to a table, the side-table indicates a member gathering of attributes of structural type.
For example, if A::=SEQUENCE {an INTEGER, b INTEGER, c INTEGER} wherein "A" denotes a syntax of an attribute in an object instance of certain MO class, "A" is allocated to the pointer, the side-table and the entry. Members a, b, c are respectively allocated to a management object item of SNMP. Namely, three management object items are defined as components of the entry.
If M-ACTION is defined in MO class, ActionInfoArg and ActionTrigger are defined as management object items in SNMP. Namely, ActionInfoArg and ActionTrigger are defined as components of an entry corresponding to the MO class. If creation or deletion of an object instance is defined, RowStatus is defined as a management object item in SNMP. Namely, RowStatus is as a component of an entry corresponding to the MO class.
However, IIMC system can not be used, if it is difficult to add to the TMN device 600 such functions of correspondence between the definition of the management information in OSI management and the definition of the management information in SNMP.
Furthermore, a load of the TMN device 600 increases in IIMC system, because the TMN device 600 supplies OSI management agent 500 and the interface 701 of the SNMP agent 700. Therefore, a service originally supplied by OSI management agent 500 may be degraded.
An object of the present invention is to provide a gateway apparatus for SNMP/OSI management which is different from the TMN agent, and is able to manage the OSI management agent by the SNMP manager, by converting the management operation and the management information.